Method for direct indication of position in a given area



Jan; 17, 1939. J. P. sHANKLlN 2,144,203

METHOD FOR DIRECT INDICATION OF POSITION IN A GIVEN AREA Filed sept. 2s, 1937 @Y mfg/ww l ATTORNEY Patented Jan. 17,I 1939 PATENT oFFlcE INAGIVENAREA nm'rnon Fo'n. manor mnlcA'rIoN 'or rosmoN .f .lohn lz'slmnklln, Marion, v. Application september z3, 1931, serial No. 165,404

claims. (ci. 25o-ll) 'I'he object of the invention is to provide aA method that makes possible, by direct reading, ones position in a given area; to .:rovide a method of the kind indicated that will give such locas tion of position whether the observation be made while the user is in motion or at rest; land to provide a method for direct indication of position that makes use only of conventional apparatus, or equipment, so that its application may be lo carried out with a minimum of expense.

With this object in view, the invention consists in a certain arrangement and employment of certain apparatus which are graphically illustrated in the accompanying drawing, wherein:

l5 Figure 1 is a view graphically illustrating an area so controlled that by the'use of conventional receiving and measuring apparatus ones position therein may be readily indicated.

Figure 2 is a. graphicalI illustration of the receiving equipment. f Y

Figure 3 is a similar view showing receiving equipment more rened than in Figure 2.

In carrying outfthe invention, transmitters are positioned at the points A and B of the controlled area and these transmitters will operate on any desired fundamental frequency. The distance between the transmitters at A' and B is arbitrarily assumed to be 1,000 kilometers, since the invention can be best understood if described in connection with xed distances. Impressed. on the fundamental frequencies of the transmitters, there is a modulation frequency whose wave length is directly proportional to the distance between the stations or transmitters. Since this distance is 1,000 kilometers, the modulation frequency had best be 150 cycles, since the wave length at this frequency is 2,000 kilometers. But the modulation frequencies are synchronized, which may be accomplished by reference to any standard frequency or by land lines, as clearly set out in Patent No. 1,942,262. With the modulation frequencies synchronized, the modulation tone from the station A will reach the station B one-half a cycle after it has left the station A'. Similarly, the modulation tone from thestation B will reach the station A one-half a cycle after it has left the station B. The two are, therefore, 180 degrees out-of-phase at the stationsor transmitters A and B with their polarities respectively reversed, but in phase at midpoint between the stationsor transmitters.

To take advantage of thiscondition, any translational means employed for translation over the controlled area is equipped preferably with `the receivers I0 and I I to be tuned respectively to the signals issuing from the transmitters at the stations A and B, the'intake ofthe receivers being connected to a common antenna I2 carried bythe translational means. 'Ihe outputs of the re- .ceivers, however, are connected to'a phase meter 5 in the other direction when the signal from the-10 transmitter or station B is leading..

As the translational means progresses, therel fore, if the receivers I0 and Il are tuned to their.;

respective stations ortransmitters, the phase relation of the modulated signals will be shown is by the phase meter, whose indicator will swing from one'V end of the scale to the other, standing in the zero or middle position at midpoint between the stations by reason of the modulation frequencies being in phase at this point. The 20 translational means may be either moving or at rest, the phase meter indicating changing position if moving, but directly indicating the point of location of the translational means if the reading be taken while the latter is at rest.

If, in addition to the one modulation frequency impressedon the carrier wave, there be also imf 'pressed additional synchronized frequencies, as for example 1,500 cycles and 15,000 cycles, greater accuracy in location of position will be obtained.

'Ihe synchronized frequencies are in geometrical progression, of which the common multiplier isten, so that on the assumed distance between stations or transmitters, the waves of 1,500 cycle frequency will fall into phase ten times and the 35 waves of 15,000 frequency times.

Where multiple modulation `frequencies are employed, the receivers I0 and I I -will be connected to the phase meter I4 through the lters I5, I6 and I1, respectively, for the cycle frequency, 40 the 1,500 cycle frequency, and the 15,000 cycle frequency, but through single-pole triple-throw switches I8 which are interconnected, as at I9, to provide'for simultaneous actuation. y

'In use, the switches I8 will be set to connect the 45 150 cycle lter in circuit when the phase meter I4 will indicate position, but not so accurately as 1 when the switches are shifted to include the 1,500 cycle filter in circuit, the 1,500 cycle lter failing to give the accuracy of reading on the phase 50 meter that will be possible when the switches are shifted to include the 15,000 cycle filters in circuit. The 150 cycle filter will indicate inv which half of the journey the translational means is located, the additional lters, upon successive use, giving 55 nnally the correct position in the area in which the observation is made. L f

In addition to locating transmitters at the taken following their tuning to the transmitters at A and B, be tuned to the-transmitters at C and D, thereby determining the position laterally'- of the line between A and B. 0r, the translational means may be equipped with receiving apparatus identical with the receivers I l and I iv and their attendant partsfso that readings between the stations A and B and the stations C and D may be simultaneously taken, thereby indicating directly ony the twophase meters the position in the direction A to B and simultaneously the position with reference to the stations C and D. Y

Having described the invention, what is claimed vas new and useful is: A

1. A method for direct indication of position in a given area -which comprisesprojecting from remote points of said area radio waves of any 2 5 differing fundamental frequencies, impressing on these wavessynchronized waves of the same'frequencies, so that the synchronized waves will have varying phase relations between said points, and then determining position at any interme- 30 diate point by the measured phase relation of the synchronized waves at that point.

2. A method for direct indication of position in a given area which compris/es` projecting 4from remote points of said 'area carrier Waves of dif- 35 fering fundamental. frequencies. impressing on these waves synchronized modulation waves whose wave length is directly proportional to the distance separating said points, Yso that there will bea progressively varying phase relation of said 40 modulation waves between said points, and then determining position at any intermediate point bythe Ameasured phase Arelation of the modulatio'n waves at that. point.

3. A method for direct indication of position in a given area which comprises projecting from `remote points of said-area carrier waves of differing fundamental frequencies, impressing on these waves synchronized modulationA waves of the same frequencies and whose wave length is A directly proportional to the distance separating said points', so that there will be a progressively varying phase relation of said modulation waves between said points, and then determiningposition ai:v any'intermediate point by the measured phase relation of the modulation waves at that point. 1

. 4. A method for direct indication of position in a given area which comprises projecting from remote points of said area carrier'waves of diifer ing fundamental frequencies. impressing on these waves synchronized modulation waves ofthe same frequencies and whose wave length is directly proportional to the distance separating said points so that there will be a progressively varying phasel relation of said modulation waves between said points, 'separately receiving the vcarrier waves at any intermediate point, and then measuring the phase relation of the modulation waves at that point to determine its position with respect to either or both of said remote points.

5. A method for direct indication of positionin av given area which comprises projecting from remote points of said area carrier waves of differing vfundamental frequencies, impressing on these waves modulation waves whosefrequencies are in geometrical progression and directly proportional to the distance between said points, the modulation waves impressed n one carrier wave Ihaving the same frequencies as those impressed on the other carrier wave and the modulation waves of like frequencies on the two carrier waves being synchronized, whereby there will be a progressive varying phase relation of the modulation waves, and then determining position at any intermediate point by successively measuring the phase relation of the modulation waves of successive pairs.

'I JOHN 1?.' SHANKUN. 

